Cigarette paper



Unitcd States Patent CIGARETTE PAPER Alexander W. Schoenbaum, Richmond,Va., assignor to The American Tobacco Company, New York, N. Y., acorporation of New Jersey No Drawing. Application June 8, 1954, SerialNo. 435,359

4 Claims. (Cl. 131-15) This invention relates to the manufacture ofpaper and more particularly to the production of a paper that isparticularly adapted for use as a cigarette wrapper.

With some of the papers now employed in the manufacture of cigarettes,small particles of partially burned paper, commonly called fly ash, willfall from a burning cigarette at frequent intervals. Sometimestheseparticles are not fully consumed, but are still burning when theyland on carpets, upholstered furniture, the smokers clothing, or thelike. They are, thus, a fire hazard and also a nuisance.

It has been suggested that paper intended for use in the manufacture ofcigarettes be treated or impregnated with various materials to produce apaper which, when used as a cigarette wrapper, will burn with formationof a non-flaking ash. Some impregnants that have been suggested for thispurpose have also been alleged to decrease the quantity of irritatinggases in the cigarette smoke. However, investigation has establishedthat many of the materials suggested, neither improve the burningcharacteristics of the paper nor produce a smoother smoke. Many of themactually produce obnoxious fumes not present in cigarette smoke fromcigarettes made with other papers.

I have found that a paper particularly suitable as a cigarette paper maybe produced by treating the paper with sodium chloride, preferably incombination with a fire retarding compound, such as carboxymethylcellulose. It has heretofore been proposed to treat cigarette paper withvarious materials including inorganic salts to decrease theinflammability of the paper. But when the sodium chloride is added topaper in an amount equal to 0.5 to 2% of the weight of the paper, itincreases the burning rate of the paper. This increase, while notsufiicient to preclude the use of sodium chloride, might beobjectionable and I, therefore, propose to add another material to thepaper which will ofiset the acceleration of burning rate proposed by thesalt addition without affecting the beneficial efiects of its additions.Various compounds may be used for this purpose. Thus, I propose to addabout 0.2% of carboxymethylcellulose with the sodium chloride.

The carboxymethylcellulose may be added in amounts from 0.1% to 1.0% byweight. Other materials which will offset the acceleration of burningrate when sodium chloride is added to the paper in the proportionsstated are gum arabic, hydroxyethyl cellulose, locust bean, tragacanth,sodium alginate, Methocel X-2602 (a water soluble hydroxpropylmethylcellulose ether) and carboxymethyl hydroxyethyl cellulose. Thesemay be used in the proportions stated above, that is, 0.1% to 1.0%.

The addition materials may be added to the paper in any suitable manner.Thus, they may be placed on the paper after its manufacture by forming asolution of sodium chloride and the retardent and applying such solutionto the paper in any suitable manner. This may be done, for instance, bypassing the paper through a bath containing the addition agents. Or theimpreg- 'ice nants may be added to the pulp prior to formation of thepaper, and the pulp then formed into sheets in the usual way.

In a specific example paper for use in cigarette manufacture wasimpregnated with substantially 1% of sodium chloride and substantially0.2% of carboxymethylcellulose by means of rolls arranged approximatelymidway of the drying section of a paper-making machine. The solution isapplied to one of the rolls by passing the roll through a tank in whichit is placed, and the paper is then fed between the moistened roll and asecond roll. In any of the methods of application the concentration ofsodium chloride and the retardent may be controlled by varying thestrength of the solution. Where the paper is passed between a pair ofrolls, one of the rolls is felt-covered. In this instance theconcentration of the addition materials can be further controlled byadjustment of the roll-pressure.

Paper treated as heretofore described forms a white ash as it burns, andthis ash shrinks around the tobacco ash forming a solid band. Itproduces a more pleasing appearance than that produced by the dark grayash which is formed when the cigarettes are made of untreated paper. Theshrinkage of the paper ash strength ens the whole ash on the end of thecigarette and almost completely prevents the dropping of fly ash.

In many instances the slight increase in the burning rate of the papercaused by the addition of sodium chloride is not noticeable. In thoseinstances that it is noticeable, the addition of the retardant shows upthe burning rate to substantially that of untreated paper. Theproportions of sodium chloride and carboxymethylcellulose given in thespecific example have been found to be satisfactory for a certain paper.If other papers are used, the amount of carboxymethylcellulose or otherretardant may be adjusted to obtain the desired burning rate.

In the final product, i. e., the cigarette, the better burning qualitiesare the only noticeable difference between cigarettes made with thepaper of the present invention and cigarettes made with other papers. Insome instances the sodium chloride additions in amounts of from 0.5% to2% by weight do not increase the burning rate a suflicient amount torequire the retardent. But when it does, one of the retardents may beused in the amount necessary to reduce the burning rate to that ofuntreated paper. In some instances cigarettes made with sodium chlorideimpregnated paper produced a milder and more pleasant smoke than that ofsimilar cigarettes made with untreated paper.

I claim:

1. A cigarette paper containing not less than 0.5% and not more than 2%by weight of sodium chloride, and not less than 0.1% and not more than1.0% of a fire retardent selected from the group consisting ofcarboxymethylcellulose, gum arabic, hydroxyethyl cellulose, locust beangum, gum tragacanth, sodium algmate, Methocel X-2602 (a water solublehydroxypropyl methylcellulose ether) and carboxyrnethyl hydroxyethylcellulose.

2. A cigarette paper containing not less than 0.5% and not more than 2%by weight of sodium chloride and not less than 0.1% and not more than 1%carboxymethylcellulose.

3. A cigarette paper containing substantially 1% by weight of sodiumchloride and 0.2% carboxymethylcellulose.

4. In the production of a cigarette paper which, on burning, produces awhite clinging ash, the step which comprises adding not less than 0.5and not more than 2% by weight of sodium chloride and not less than 0.1%and not more than 1% by Weight of a fire retardent select- 3 ed from thegroup consisting of carboxy mcthylcellulose, gum arabic, hydroxyethylcellulose, locust bean gum, gum tragacanth, sodium alginate, MethocelX-2602 (a water soluble hydroxypropyl methylcellulose ether) andcarboxymethyl hydroxyethyl cellulose to the paper.

References Cited in the file of this patent UNITED STATES PATENTS 4Finley Sept. 6, 1927 Morton Sept. 21, 1943 Sartoretto et a1. Oct. 14,1952 Samfield et a1 May 10, 1955 FOREIGN PATENTS Great Britain June 26,1930 OTHER REFERENCES Scientific American, July 21, 1894, page 38,Fireproofing Compounds.

1. A CIGARETTE PAPER CONTAINING NOT LESS THAN 0.5% AND NOT MORE THAN 2%BY WEIGHT OF SODIUM CHLORIDE, AND NOT LESS THAN 0.1% AND NOT MORE THAN1.0% OF A FIRE RETARDENT SELECTED FROM THE GROUP CONSISTING OFCARBOXYMETHYLCELLULOSE, GUM ARABIC, HYDROXYETHYL CELLULOSE, LOCUST BEANGUM, GUM TRAGACANTH, SODIUM ALIGINATE, METHOCEL X-2602 (A WATER SOLUBLEHYDROXYPROPYL METHYLCELLULOSE ETHER) AND CARBOXYMETHYL HYDROXYETHYLCELLULOSE.